The present invention relates to scanning devices, and in particular, a scanner that saves raw scanned data in an image buffer for utilization in a prepress image scaling mode.
The terms used herein have the same meanings as in the digital printing and scanning sciences. Likewise, it will be understood that the usefulness of the present inventions and discoveries is not limited to these, although it is in connection with such that the inventions hereof presently have principal usefulness. The term xe2x80x9cinventionxe2x80x9d will be understood to be inclusive of discovery.
In document scanning, a user scans his original and captures a digital image in a host computer or workstation. If the image captured isn""t acceptable for printing or otherwise publishing, the scanner parameters are adjusted and the image is rescanned and processed. If the user captured the image in full resolution, he/she may use the captured image and process the image in many different ways on the host system. The time it will take to make and process the adjustments can be quite long due to the large image processing activity required by the host workstation. Image adjustment to compensate for scanner parameters is therefore cumbersome and time consuming.
The problem is further exasperated in the field of high volume scanners. These type of scanners take a stack of original documents and feed them seriatum through an image capturing device. If any of the scanned image is not acceptable due to scanner parameters, the entire stack of originals must be reloaded and rescanned in order to maintain the unacceptable images in their proper order.
A further problem with scanners is their utilization in image or document enlargement/reduction operations, known as scaling. Typically, enlargement scaling is achieved by decreasing the scanner motor speed, which reduces the speed by which the original is passed by the scanning head. This method is used since the image processing hardware has a fixed maximum bandwidth. The increased processing time needed is directly proportional to the scale factor. For example, a 200% enlargement increases the amount of processing time by 200%, thus the motor speed is cut to half speed. For scanners supporting 400% enlargement, the motor control system must be able to operate properly and smoothly over the range of one fourth speed to full speed. Another way of looking at this range is the maximum scanning speed is three times the slowest scanning speed. This method of scaling also suffers due to finite impulse response (FIR) filtering problems. FIR filters are designed for a specific image aperture. By changing the scanning speed the intrack aperture has effectively been changed. The filters can be changed to accommodate different aperture, but supporting a FIR filter that is not symmetrical is not a simple task or cost effective solution.
Efforts regarding such systems have led to continuing developments to improve their versatility, practicality and efficiency.
An object of the present invention is to provide a scanner which stores raw image data in an data buffer, and provides an operator the opportunity to review the raw data and manipulate it in a prepress mode prior to printing or otherwise reproducing the image.
Another object of the present invention is to provide a scanner which permits scaling without changing scanner motor speed.
According to the present invention, a scanning system operated by an operator to convert printed material to electronic data utilized by a user device including a transducer to convert light into raw digital image data (DID); an image processor to receive the raw DID and manipulate the raw DID and to provide manipulated DID; an output data path to provide data to the user device; a memory buffer to store data; and, a controller to control whether the DID is stored in the memory buffer, or is manipulated by the image processor, or is provided on the output data path, or is manipulated by the image processor then stored in the memory buffer.
The present invention provides a useful prepress mode for a scanner, since not all scans are acceptable to a viewer the first time. Permitting an operator the ability to review a scanned image, edit it, and rereview without an additional scan is highly beneficial.
To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative embodiments of the invention. These embodiments are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.